Crossair Flight 3597 Analysis: Too Little, Too Late?
The Pilot In Command who had amassed nearly 20,000 flight hours took the flying role for this flight, the First Officer who had just under 500 hours of flight time handled the radio communications and navigation for the flight into Switzerland. For the most part the flight was uneventful until it reached its final few stages. After receiving the ATIS (Automatic Terminal Information Service) and selecting the approach for the runway, things started to take a turn for the worse.
On this flight the crew advised the tower that they had ‘ATIS information KILO,’ from this they derived that they should set up for the ILS Runway 4 approach. However, a few moments later the ATIS information had changed from Kilo to November therefore the crew were working on old information in regard to the conditions at the airport. The AOPA state that;
“The identification letter of the ATIS is vital.”
ATC did not inform the crew of the change in ATIS, therefore the pilots had no reason to believe that the weather had deteriorated. It’s rare for a pilot to get the ATIS more than once unless there is a delay or the estimated time of arrival has increased substantially.
Shooting an approach, especially non-precision, without the most up-to date weather is extremely dangerous especially if the weather is close to the minimum decision altitude. If the pilot had a clearer idea of what to expect as he got closer to the MDA he may have been able to be more decisive in his decision making.
The controller told the crew to expect the Runway 28 VOR/DME approach. Since this is a non-precision approach workload is increased. As the crew did not obtain radar vectors for this approach, they were shooting it using their own navigation without the help of ATC. It is important to note that at Zurich Airport Runway 28 does not have a Minimum Safe Altitude Warning System. MSAW informs ATC when an aircraft has violated altitude minimums, an audio and graphic warning is displayed to the controlling agency. This significantly prohibited the tower in providing any help to the crew, as warning them about their low altitude could have helped.
As the pilot neared the final approach segment and is 6 nautical miles from the airport, the established altitude is 3,360ft MSL as indicated on figure 1.However, data provided by wider media states that the aircraft is at 3600ft 6nm from the airport. This is 360ft below the prescribed altitude. Moreover, it has been stated that the aircrafts descent rate was in excess of 1,000ft which is unusual because looking at the Groundspeed/Descent Gradient in figure 1, if the aircraft was approaching at the max ground speed of 160 knots the descent gradient shouldn't have exceeded 859. It also doesn’t make sense as to why the aircraft was descending so rapidly since it was already lower than published.
The voice data recorder shows that prior to arriving at the MDA the PIC announces that he has visual contact with the runway environment, the first officer acknowledged and agreed. Whether both pilots actually saw the runway is open to debate. If the First Officer did not have the airport environment in visual he should have told this to the PIC instead of just agreeing. When conducting instrument approaches in flight training it is often the ‘safety pilot’ who monitors the instruments and advises the PIC when the runway environment is in sight. The PIC should only be concentrating on flying the aircraft. However, in this situation it is the PIC who verbally announced he had the runway in sight.
The visibility reported at the time the pilot allegedly saw the runway was approximately 2KM. Figure 2 above shows the visibility at 5KM and the runway is barely visible. It's hard to imagine that the flight crew actually saw the runway lights or the threshold with only 2KM of visibility.
Since the crew questionably determined that they had the airport environment in sight they continued to the MDA. After passing through the MDA of 2,390ft the aircraft should have levelled off and continued to the MAP, standard practice when shooting a non-precision approach. However, the PIC starts to descend more. It's tempting when flying in such conditions to continue descending as you desperately seek the runway, however this kind of mentality can have fatal consequences. The numbers on the published approach chart are there for a reason, they take you to an altitude that is safe and that allows you to have enough time to climb if you have to execute a missed approach. It’s vital you stick to the published numbers.
SAIB (2001) ‘Final Report No. 1793 by the Aircraft Accident Investigation Bureau’, AAIU, (1), p. 1. Available at: http://www.aaiu.ie/sites/default/files/SAIB Switzerland Accident AVRO 146-RJ HB-IXM near Bassersdorf Zurich 2001-11-24.pdf.
Stocker, T. (2016) ‘Pilot blamed in Crossair crash; others implicated’, p. 1. Available at: https://www.ainonline.com/aviation-news/aviation-international-news/2007-03-16/pilot-blamed-crossair-crash-others-implicated.
Fear Of Landing (2013) ‘Controlled Flight into Terrain’, p. 1. Available at: https://fearoflanding.com/accidents/accident-reports/controlled-flight-into-terrain/.
FAA (2018) ‘In this Issue: PIREP Solicitation — MVA vs MSAW — MSAW Expectations vs Function’, FAA, (June), pp. 2–6. Available at: https://www.faa.gov/air_traffic/publications/media/atb_june_2018.pdf.Fries, B. (no date)
‘The Best of Flight Training Magazine Just the Facts Filtering out fluff in radio communication ( With apologies to Yogi Berra .) Why is it that older , experienced pilots can decipher radio communications better when hearing typically diminishes with age’, AOPA, pp. 1–5. Available at: https://www.aopa.org/-/media/Files/AOPA/Home/Training-and-Safety/Flight-Training-Resources/Just-the-Facts_Radio-Communication.pdf.